Safety seat belt buckle



March 18, 1958 F. 1.. DAVIS SAFETY SEAT BELT BUCKLE Filed March '1, 1956Fig. l

. INVENTOR.

FRANK L..,DAV1S ATTORNEY 2,826,796 SAFETY SEAT BELT BUCKLE ApplicationMarch 1, 1956, Serial No. 568,732 1 Claim. (Cl. 24-170 The inventiondisclosed relates to belt buckles of the type covered in copendingpatent application Serial No. 493,150, filed March 9, 1955, in which thebelt webbing is held by a spring closed cam which can be released bylifting a lever handle extension connected with the cam.

The free end of the strap or webbing normally extends out of the bucklebeneath this releasing lever.

The present invention is based on the realization that under crashconditions this free length of webbing can act with powerful leverageeffect to momentarily lift the cam lever sufficiently to release thewebbing and thus nullify the whole effect of the seat belt. Under suchconditions the seat belt actually becomes an element of danger, creatinga sense of safety not to be relied on in the event of a crash.

The objects of the present invention are to guard against thepossibility of accidental release of the belt buckle and to accomplishthis with simple, practical structure applicable to buckles presently inuse, such as disclosed in the identified patent application.

Further special objects of the invention are to provide this safetyfactor in a form which will not add to the bulk or weight of the buckle,which will not alter the regular and understood use of the buckle andwhich in fact will actually aid in the proper use of the buckle,particularly in insuring the proper reeving or engagement of the webbingwith the buckle.

The foregoing and other desirable objects are attained by novel featuresof construction, combinations and relations of parts as hereinafterdescribed and claimed and illustrated by way of example in the drawingaccompanying and forming part of this specification.

While the structure shown may be considered as exemplifying thepresently preferred form of construction, it will be apparent from thedescription and claim following that structure may be modified andchanged as regards the immediate illustration.

Fig. 1 in the drawing is a plan view of the buckle with the anti-releasesafety feature incorporated;

Fig. 2 is a side elevation of the buckle;

Fig. 3 is a longitudinal sectional view of the buckle as onsubstantially the plane of line 3-3 of Fig. 1 but showing the webbingconnected therewith and the cam in closed position;

Fig. 4 is a view similar to Fig. 3 but showing the effect under crashconditions of the free end portion of the webbing snapping outward butconfined by the overstanding guard against cam-freeing contact with theend of the lever.

The buckle shown is like that disclosed in copending patent applicationSerial No. 493,150, consisting of a sheet metal frame made up of a ingflanges 6, 7 carrying stud 8 on which the spring closed cam 9 ispivoted, said cam having a hand lever 10 extending toward or beyond theopposite end of the buckle and by which the cam may be lifted away fromthe companion pad portion 11 of the buckle to release it from holdingengagement with the strap or webbing 12.

nited States Patent The latter may be considered the free or adjustableportion of the belt, the other section 13 of webbing being looped orotherwise non-adjustably secured to the buckle at 14 and being anchoredto some fixed portion of the vehicle or other structure on which thebelt is used.

Fig. 3 shows how under normal riding conditions the free end of theadjustable length of webbing, which is usually made heavier by athickened or reinforced handle or terminal portion 15, will ordinarilyextend practically straight out of the buckle and lie close over thefixed length of webbing 13.

base portion 5 having upstand- Fig. 4 shows how with a sudden stopresulting from crashor other extreme conditions, the free, weighted endof the webbing will fly outward or forward, operating as a leverpowerful enough in many cases to momentarily lift the cam lever.

The present invention eliminates this danger by provision of a guardoverstanding the free portion of the webbing within the buckle andforming a barrier preyenting such free portion from engaging the camlever.

Specifically this guard is shown as a light sheet metal spring plate 16interposed between the base of the buckle and the lever, in front of theearn 9 and companion pad 11, and shown as supported in that relation byside flanges 17 at the edges of the plate closely engaging the flanges6, 7 and riveted thereto at 18.

To overcome any rocking tendency and to positively secure the guardplate in position substantially parallel to the base wall 5, one of theflanges 17, the lower one in Fig. l, is shown as having a forkedextension 19 engaged over the pivot stud 8 between flange 17 and theadjoining end of cam 9.

The ends of the guard plate 16 and adjoining portions of the supportingflanges 17 are shown as cut away at 20, Figs. 1 and 3, to lighten theguard structure and to give these parts a yielding springcharacteristic, enabling the guard to be yieldingly gripped between theside flanges of the buckle and permitting the plate itself to yield to aslight extent to cushion the snapping action of the webbing.

In addition to preventing the webbing from releasing the earn, theguard, overstanding the free length of webbing, actually shortens thelength of leverage that the webbing could apply to the cam lever.Without this guard the free portion of the webbing would have a tendencyto pivot from a point A, Figs. 3 and 4, where it is to be held by thecam. The overlying guard shortens this possible leverage to the pivotalpoint B, thus reducing the inertia effect as Well as actually preventingany dangerous exercise of that effect.

Additionally, also, the overstanding guard serves as a guide fordirecting the free end of the webbing through the buckle, enablinganyone unfamiliar with the buckle to readily enter and feed the webbingthrough the buckle. The guard does not add in effect to the weight anddoes not encumber or add bulk to the buckle. The cost is low but allthese advantages are much outweighed by the non-accidental releasesafety factor provided by the invention. Also, the guard is below andout of the range of action of the cam lever and so does not limit orrestrict the operation of the web holding cam.

The guard further prevents accidental release of the cam by pullingoutwardly on the free end of the webbing.

Extending as it does practically from the cam out to the end of thebuckle, the guard plate assures that the webbing entered in the end ofthe buckle will pass properly beneath the cam and out the far end of thebuckle. This plate, while normally beneath the range of web clampingmovement of the lever so as not to limit or restrict the web clampingand holding action of the cam, by reason of its springy construction mayyield inwardly 3 if the lever be hammered or forcibly pressed inwardlytoward the back or base of the buckle.

The spring guard plate can be manufactured at low cost and can beinexpensively installed in seat buckles now in use, thus to convert themto anti-crash-rcleasing safety seat belt holding buckles.

What is claimed is:

Anti-crash-releasing safety seat belt buckle comprising the combinationof buckle frame and cam pivoted in said frame in position to grip andhold a free length of webbing extended through the buckle, said camhaving a releasing lever extending longitudinally of the frame over thewebbing gripped by the cam and a guard mounted in the frame in positionover the webbing gripped by the cam and disposed beneath the end of saidreleasing lever in position to prevent the free end portion of thewebbing extending beyond the lever from lifting the lever in the camreleasing direction of movement, said guard being in the form of a thinsubstantially flat plate extending substantially from the cam to the farend of the buckle in substantial parallelism with the webbing held bythe cam and held in such relation by engagement with the pivot mountingof the cam at one end and by engagement with the buckle frame of theopposite end.

References Cited in the file of this patent UNITED STATES PATENTS

